Projector stacking stand

Abstract

A projector stacking stand for supporting at least one image projector comprises a frame and at least one mounting platform connected to the frame with ends supporting an image projector. Each mounting platform is connected to the frame for enabling adjustment of the pitch, roll and yaw thereof relative to the frame by means of a gimbal having three discrete pivot axes corresponding to pitch, roll and yaw axes. The gimbal is moved about the pitch and roll axes by two shafts, each mounted on the gimbal for independent rotation with the axis thereof disposed parallel to the pitch axis and a cable for each shaft having at least one turn therearound. Each cable is connected to the frame under tension with a portion above and below the turn around the shaft and each shaft is rotatable to effect vertical movement thereof along its cable, whereby pitch adjustment is obtained by rotating the two shafts simultaneously in the same direction and roll adjustment is obtained by rotating the shafts individually. The platform is rotatable about the yaw axis relative to the gimbal for yaw adjustment.

What is claimed is: 
     
       1. A projector stacking stand for supporting at least one image projector, comprising: a. a frame;   b. at least one mounting platform for supporting an image projector;   c. means connecting said mounting platform to the frame for enabling adjustment of the pitch, roll and yaw thereof relative to the frame, the connecting means comprising; i. a gimbal having three discrete pivot axes corresponding to the pitch, roll and yaw axes,   ii. means for moving the gimbal about the pitch and roll axes comprising at least one cable having at least one turn around cooperating shafts, means connecting the cable to the frame under tension and means for rotating each shaft to effect movement of each shaft along its cable, whereby pitch and roll adjustments are obtained by rotating the shafts and   iii. means for rotating the base about the yaw axis relative to the gimbal     wherein the means for moving the gimbal about the pitch and roll axes comprises two shafts, means mounting each shaft on the gimbal for independent rotation with the axes thereof disposed parallel to the pitch axis, a cable for each shaft having at least one turn therearound, means connecting each cable to the frame under tension with a portion above and below the turn around the shaft and means for rotating each shaft to effect vertical movement of each shaft along its cable, whereby pitch adjustment is obtained by rotating the two shafts simultaneously in the same direction and roll adjustment is obtained by rotating the shafts individually.   
     
     
       2. The projector stacking stand according to claim 1, wherein the frame comprises four parallel vertical members with two front and two rear members disposed in parallel transverse rows, wherein the pitch axis of the gimbal is vertically fixed in the two rear members and the means connecting the cables to the frame is disposed at the two front members and comprises first and second cylindrical members each fixed horizontally to a front member on one side of the shaft and about which the cable is looped and means fixed to the front members on the other side of the shaft and connected to the ends of the cables and including springs applying tension to the cables. 
     
     
       3. The projector stacking stand according to claim 2, further comprising means for releasably locking the base in position comprising means for preventing rotation of said shafts. 
     
     
       4. The projector stacking stand according to claim 2, wherein the means rotatably mounting each shaft comprises means applying a friction force thereon to prevent free rotation of the shaft. 
     
     
       5. The projector stacking stand according to claim 1, wherein the cable comprises nylon jacketed stainless steel. 
     
     
       6. The projector stacking stand according to claim 1, wherein the means rotating the base about the yaw axis comprises a third shaft, means rotatably mounting the shaft on the gimbal, a third cylindrical member fixed to the base on one side of the shaft, a third cable having at least one turn around the third shaft and looped around the third cylindrical member and means connecting the ends of the third cable to the base on the other side of the shaft with the third cable under tension. 
     
     
       7. This projection stacking stand according to claim 1, wherein the two shafts providing pitch and roll adjustment are loosely coupled together so as to limit their relative rotation and thereby to limit the amount of roll adjustment permissible.